Using `pkg-config` in CMake is fairly easy:
```cmake
-cmake_minimum_required(VERSION 3.0)
-
-cmake_policy(SET CMP0048 NEW)
-project(my_gtest_pkgconfig VERSION 0.0.1 LANGUAGES CXX)
-
find_package(PkgConfig)
pkg_search_module(GTEST REQUIRED gtest_main)
-add_executable(testapp samples/sample3_unittest.cc)
-target_link_libraries(testapp ${GTEST_LDFLAGS})
-target_compile_options(testapp PUBLIC ${GTEST_CFLAGS})
+add_executable(testapp)
+target_sources(testapp PRIVATE samples/sample3_unittest.cc)
+target_link_libraries(testapp PRIVATE ${GTEST_LDFLAGS})
+target_compile_options(testapp PRIVATE ${GTEST_CFLAGS})
-include(CTest)
+enable_testing()
add_test(first_and_only_test testapp)
```